The star of Teen Mom OG is opening up about that epic meltdown that occurred while he and Amber Portwood were in Las Vegas for a friend’s wedding — and admitted that he relapsed and was using drugs at the time.

“I had a drug relapse this year for the first time with prescription pills. I fell back into my addiction for about two months around December,” he tells People. “I was taking a good amount of pills and I was killing the pain. Before I knew it, I was back in the cycle again and completely off my program. I was still convincing myself that it wasn’t as bad as it used to be but it was.”

During the now-infamous meltdown, he declared that Amber “wanted to marry her brother,” before insisting that he “will not marry her ever!”

Things got worse when he and his on-again, off-again fiancé went to NYC for a business trip and he experienced a two-day blackout — and it was then that he realized he was in desperate need of help after a higher-up at MTV called him on his BS.

“The last time I took pills was roughly around four months ago when I was in New York. That was a big slap in the face. We went out for a press day for a couple of days and after we finished the trip, we went to LA to film something. [While there] I saw one of the __ executives and I asked them a question,” he says. “He looked at me and said, ‘Matt, we had a two-hour conversation about this already. I didn’t remember the conversation or even seeing him in New York. I barely remembered the trip. That was the turning point for me, I had just blacked out an entire two-day trip, I have a problem again.”

He insists that Amber didn’t know he was using at the time — adding that he never used around her eight-year-old daughter Leah — and says that when he did come clean to Amber, she was supportive of him getting back on the wagon.

“I would never want to go back to this life. I spent a lot of years sober and I was disappointed and ashamed that this happened but I am also going to grow from it,” he says. “Now I have zero desire for it.”

Scroll through the gallery to see how your favorite Teen Mom stars met their significant others!

Amber Portwood and Matt Baier

The engaged couple met through the power of the Internet! Matt — who claimed not to be familiar with Teen Mom, despite evidence proving he reached out to both Jenelle and Farrah — won Ambie over through his tweets!